Only a handful of French guns were positioned at the centre of Victor’s line and they spat back their defiance, trading shots with the batteries immediately opposite. All the time Victor’s guns were whittled down by the enemy until, no more than a quarter of an hour after the cannonade had begun, the last French eight-pounder was struck squarely on its carriage and a hail of splinters cut down half of the gun crew. The survivors turned and ran for the lines of infantry waiting behind them.

The Austrian guns fell silent, then a moment later the sound of drums and trumpets reached Napoleon. Through the dense bank of gunpowder smoke emerged columns of enemy infantry, the sun glinting off their musket barrels and the officers’ gorgets and swords as they waved their men forward. There was a lull in the noise of battle as the enemy came on, and the French waited, grimly. Then, when it seemed that the two lines could not get much closer, Napoleon heard the order to present arms echo down the French line.Thousands of musket barrels swept up and out, aiming at the enemy no more than seventy paces away.

‘Fire!’Victor bellowed, his booming voice carrying across the battlefield. Stabs of light and swirls of smoke billowed out along the French line like a ribbon of soiled cotton. From his slightly elevated position Napoleon could see the leading ranks of the enemy column tumble down as the volley of musket balls tore into them. But they held their ground, re-formed and marched a short distance closer before deploying into a firing line. Victor’s men managed to get off two more volleys before the Austrians returned fire. Then the fight was swallowed up in an ever-thickening bank of acrid yellow smoke that hung across the battlefield.

Napoleon waited until he was certain that the French line was holding along its front, and then rode forward to General Victor. The veteran greeted him with a salute and a wry shake of the head. ‘They caught us out nicely, sir.’

Napoleon ignored the comment as he returned the salute. ‘You must hold here for as long as possible. Lannes and Murat are moving up to support you. I’ve sent for Desaix.’

‘Desaix? He won’t be able to reach us until long after this battle is over.’

‘Perhaps,’ Napoleon conceded. ‘But he might. Meanwhile we have to hold the Austrians back as long as we can, until tonight at least.Then we’ll concentrate our forces and go on to the attack tomorrow.’

‘If there are any forces left to concentrate,’Victor said quietly. He glanced towards his men, now firing by companies in a continuous rattle of musket fire. ‘Besides, we’re going to run out of ammunition before long. Then we’ll be at their mercy.’

‘If that happens, we’ll fall back on the main camp and resupply the men from there.’

‘Yes, sir.’

‘Remember, Victor.’ Napoleon thrust his arm towards the ground.‘Hold here for as long as possible.That is our only chance of surviving this day.’

‘Yes, sir.’

Napoleon wheeled his horse round and rode along the rear of his line. Whenever the men noticed him, a cheer rose up, before the sergeants and officers bellowed at them to face front and keep firing. The first of the walking wounded were already staggering back from the foremost ranks, clutching their bloody injuries as they made for the rear. When he reached the end of the line it was clear to Napoleon that the main weight of the enemy attack was being thrown at General Watrin’s division, on the right flank. The dead and wounded lay thick on the ground and as the survivors closed ranks, the gaps in between units were growing all the time. So that was the enemy’s plan, Napoleon nodded to himself. Melas intended to crush the French right, then send his cavalry in a sweeping arc to trap the French army against the Bormida and crush them.

Watrin was having his arm bandaged as Napoleon rode up to the small cluster of divisional staff officers.

‘Not serious, I hope.’ Napoleon gestured towards the injury.

‘A flesh wound, sir. That’s all. Nothing compared to what’s happening to my men.’ He glanced at the smoke shrouding his line. Only the rear ranks were clearly visible. In front of them the men in the front lines were no more than dim grey shapes, firing, reloading and firing again. ‘They’re carving us up, sir. I doubt we’ll be able to hold this position for another ten minutes.’

‘You have to,’ Napoleon replied bluntly. ‘Reinforcements will be on the way.You have to hold the enemy back until they arrive. Whatever the cost. Is that clear?’

‘Yes, sir.’

‘Then God be with you, General.’

‘And you, sir.’

By the time Napoleon had returned to his command post on the raised ground behind Marengo, the Austrians had pulled back their battered assault columns and were preparing another attack. As the smoke dispersed and lifted from the battlefield the perilous situation of the French army was clear for all to see.The ground was littered with the dead and wounded of both sides, but whereas the battered units of Napoleon’s army were spread thinly across the ground the enemy were able to mass fresh battalions to continue the fight, and these were forming up, preparing for the next assault.

Berthier approached him, clutching a scribbled note. ‘Victor’s men are down to their last few rounds, and we have only fifteen pieces of artillery left. Victor asks for permission to withdraw before the next attack begins.’

‘No. He must stay where he is.’

‘But, sir,Victor cannot hold them back.’

‘Then he must delay their advance for as long as possible.’

‘At least reinforce him then. We still have Monnier’s division in reserve.’>

Napoleon turned and pointed towards Castel Ceriolo. ‘We need Monnier there. He must hold the flanks.Watrin’s division is all but finished. Give the order for Monnier to advance immediately.’

‘What about Watrin, sir? Should I pull him back?’

Napoleon shook his head, even though he knew that Watrin’s division must collapse under the next attack, unless they were supported. But Monnier’s men were the only forces available to send into the battle and they had to hold the flank. Then Napoleon’s gaze fell on the men of the Consular Guard, two thousand strong and every man a tough veteran.

‘Berthier, send the Guard forward to support Watrin.’

His chief of staff was shocked.‘The Guard? But, sir, if the army breaks and routs, who will protect you?’

‘If the army breaks then I will be beyond need of protection,’ Napoleon replied quietly as he gripped the hilt of his sword. ‘Send the Guard forward.’

Berthier nodded solemnly and turned back to his campaign desk to hurriedly write the orders and hand them to the waiting dispatch riders. As the last of them rode off, he returned to Napoleon’s side.

‘That’s it then, sir. We’ve no more men to put into line against the enemy now. We’re in the hands of fate.’

‘Fate won’t decide this,’ Napoleon replied. ‘It’s a test of courage and endurance . . . And numbers.’

Berthier smiled mirthlessly. ‘Fate has a way of favouring the bigger battalions.’

Napoleon did not reply, but stared out over the battlefield at the Austrians surging forward to attack his thinly stretched army. Could they weather another assault, he wondered? If not, then only Desaix could save them from utter destruction.

After a fresh cannonade the Austrian columns came on again.To the right, opposite the end of Watrin’s division, a large body of cavalry was forming up behind the columns of Austrian infantry. The Consular Guard formed into a square before it marched steadily forward to fill the gap between Watrin’s and Monnier’s divisions.As the enemy saw the guard moving towards them, they turned their attention away from the remnants of Watrin’s division and opened fire on the square. At such close range the veterans were shot down by the score under the withering volleys of the enemy. But each time they steadily closed ranks and continued forward, until at last the order was given to halt, and open fire.